Compact hand-held RF data terminal

ABSTRACT

A compact, hand-held data terminal includes a data display and an alpha-numeric keyboard and a bar code reader provision for manual data entry. The data terminal further includes an RS 232-C data interface for downloading accumulated data into a central computer. The data terminal further includes a transceiver module which provides for an RF communications link to a central computer. An antenna for the transceiver module is contained within the a lower portion of the housing of the data terminal along side walls of a battery compartment. In operation, the data terminal may be inserted into a data transfer cradle coupled to data processing equipment, thereby coupling the data processing equipment via the RF link to the central computer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to the field of communications and alsoand more particularly to communication systems including portable,hand-held transceiver terminals.

2. Description of the Related Art

In the past, users of computer-supported data processing systemstypically were restrained by limited availability or a lack of devicesfor conveniently interacting with existing computer systems. Duringchanges from existing bookkeeping or accounting systems to computersystems to existing bookkeeping or accounting systems procedural changeswere typically minimized. Consequently, conventional data entryprocedures usually remained in effect. Adherence to existing procedureswith the concurrent use of computer systems did in many instances impedethe effective implementation of computer systems. For example, incommercial activities which traditionally relied on written logs orrecords, the practice of making written records and transcribing therecords to electronic, computer-maintained data bases typicallycontinued without recognition that an unnecessary duplication of effortswas involved. The duplication occurred by initially generating writtenrecords as it had been done in the past, and then transcribing thewritten records to electronic data bases. Efforts to make computers moreaccessible have in the more recent past resulted in the development ofportable data terminals which interface with computers.

Two types of portable data terminals have found considerable use incommercial systems relating to merchandise delivery, warehousing andinventory keeping systems. Both types of data terminals are portable.They characteristically include portable power sources of sufficientstorage capacity to power the respective terminals over the entirelength of contemplated working periods. The working periods mayconstitute the length of a normal working day or an even longer period.

A first type of data terminal is found to be particularly adaptable tothe generation of delivery records or customer invoices, such as thosetypically generated in delivery route operations. A strength ordesirable feature of the first type of terminal is that it isself-contained. A delivery route driver typically carries the terminalwith him on the delivery route, such route could conceivably includemany stops. The stops may be planned to be made in predetermined order,or at other times they may be chosen at random. Variable modes of usageand application need to be served by terminal-resident recording andprocessing circuits. Because of the self-contained mode of operation ofthe first type data terminal, typically, a substantial portion ofavailable housing space is taken up with memory boards. Memory space isneeded in form of random access memory circuits for storing data, andalso as preprogrammed circuits for routine functions which minimize thework effort by a driver or delivery man and make the terminal a timesaver. Data stored in such first type of terminal are typicallytransferred or "down loaded" to a central computer in a batchtransaction after the delivery trip has been completed.

The second type of portable terminal is adapted for use in warehouses orin merchandizing establishments to generate, for example, real timeinventory records. In distinction over the first type of terminal, usagerequirements of the second type of terminal typically involve handlingor recording an even greater number of data, typically relating tomerchandise items. Also in contrast to the first type of terminal, theneed for mobility of the second type terminal differs by nature of theapplication. Typically, the second type terminal needs to be fullyoperational only within the confines of a designated, restricted area,such as a stockroom of a merchandise building, or within a somewhatlarger area of a warehouse. In such a relatively restricted space, adata terminal is ideally equipped with a typical RF transceiver tocommunicate via a base transceiver station with a central computer.

The second type terminal, instead of having a large electronic memory ora substantial circuit section with pre-programmed functions,consequently need include only a minimum of memory and pre-programmedfunctions in addition to such a transceiver circuit. Typically apredetermined number of the transceiver-equipped data terminals arecoupled by means of a multiplexing scheme through the base transceiverstation to the same central computer. A distinct advantage of suchRF-coupled communication link is that a comparatively light and small,hand-held terminal possesses a data processing power and data storagecapacity which is limited only by the power and capacity of a centralcomputer to which it is communicatively connected. Another advantage ofdirect, interactive communication between the hand-held terminal and thecomputer is that data files of the central computer are updated on areal time basis and that each additional terminal coupled to the samecentral computer has the benefit of the most up-to-date information.

The two types of hand-held data terminals have developed in parallel andare distinct in design in spite of some similarities. One outward andimmediately apparent distinction, in many cases, between the two typesof data terminals is the presence of antennae on transceiver type ofterminals. Until recently, all transceiver type of data terminals havefeatured such antennae. Only recently some hand held units have beenmarketed with internally located antennae, such as a hand set of acordless telephone or a commercial data terminal manufactured byMotorola, for example. Using conventional transceiver type dataterminals brings the realization of the inconvenience caused by thepresence of the antennae. The extending antennae are easily damaged orbroken off. Even flexible type antennae are damaged, when they areaccidentally jammed against a wall in a crowded stock room or when theyare carelessly used as a carrying handle. In spite of such shortcomingsof external antennae, to maintain optimum transmission ranges, the useof external antennae has prevailed in most instances.

Where it does become desirable to eliminate external antennae, andparticularly in those applications where the transmission range may notbe decreased by relocating the antennae to within the housing of thehand-held terminal, the size of the hand-held terminal is apt toincrease accordingly. In short range devices for voice communication,rather than for data communication, such as a handset of a cordlesstelephone, the use of untuned antennae in the form of a single wirelooped within the housing of the handset has been used to eliminate theexternal antenna without increase of the size of the handset. Forinteractive data terminals, on the other hand, the use of tuned antennaefor accuracy in data transmission becomes desirable. Thus, dataterminals in most cases are still using conventional external antennaewhich may be tuned to optimize their performance.

In addition to the above-mentioned disadvantages of external antennae,the existence of external antennae is an external, physical distinctionof the second type of portable terminal with respect to the first typeto cause certain undesirable incompatibilities between the two typeterminals. It would be desirable, for example, to use the sameperipheral devices, such as printers, for both types of terminals. Thepresence of the antennae typically cause physical interference,particularly when connector cradles are provided to establish theconnection to the peripherals. In those instances, the antennaetypically interfere with the attachment of such peripheral devices tothe terminals. One solution to the latter problem is to provide specialconnectors to eliminate such interference. This solution is cumbersomeand undesirable in most instances.

SUMMARY OF THE INVENTION

The present invention seeks to overcome incompatibilities between thediscussed first and second type portable data terminals by a portable,hand-held transceiver type data terminal of the second type having anexternal configuration in size, shape and appearance substantiallyidentical to a hand-held data terminal of a first type with thecapability of batch mode data transfer to a central computer.

According to one broad aspect of the invention, a compact, hand-heldterminal of such second type includes a housing with a keyboard in afront face to manually enter data. A display terminal is coupled to thekeyboard. The terminal further includes electrical contacts mounted inthe housing and connected to circuits within the terminal to permit thetransfer of data directly through the contacts between the terminal andexternal peripheral devices. A transceiver module mounted within thehousing is coupled to control circuits and has the ability tocommunicate via an antenna located within the housing.

In another aspect of the invention, the internal antenna includes ahelical radiating element disposed at the periphery of a batterycompartment of the data terminal. The helical radiating element may becomprised of two helical elements located at opposite sides of thebattery within the housing, and as such at peripheral edges of a groundplane formed on a circuit board supporting the control circuits of thedata terminal.

In one aspect of the invention, the electrical contacts of the dataterminal include a communications connector capable of being coupled toa printer. Such communications connector is in a preferred embodiment ofthe invention disposed on at least one end of the housing, and the dataterminal is adapted to be inserted into a cradle including a connectormating with the connector of the data terminal. In accordance withanother aspect of the invention, the data terminal includes a secondconnector, and a bar code reader releasably connected to the dataterminal via said second connector. The bar code reader is therebyreleasably coupled to control circuits of the data terminal. The barcode reader may be removed when the data terminal is to be inserted intosaid cradle for coupling the data terminal to said peripheral device.

A particular advantage of the invention is the compatibility of the dataterminal with existing peripheral devices, such as printers for use withportable data terminals which do not include transceivers for RFcommunications with a host computer.

Another advantage of the invention as described herein after is that thelocation of the antenna within the housing of the data terminal permitsthe data terminal to be inserted into a standard, available cradle tocouple the data terminal to standard data and power contacts ofperipheral devices, as are currently available to the data terminal ofthe first type.

A particular advantage may be realized by the invention described hereinupon connection of the data terminal to a standard data transfer cradlefor data terminals without RF communications capabilities. Such datatransfer cradles are connected to host computers for receiving in adirect data transfer mode data from such data terminals without RFcommunication capabilities. In connecting the data terminal inaccordance with the invention to such a data transfer cradle, twodistinct host computers may be linked via the data terminal for datatransfer there between. The use of the data terminal consequently notonly meets but surpasses the combined capabilities and advantages of thereferred to first and second type data terminals.

These and other of the various features and advantages of the inventionwill be best understood by the following detailed description of apreferred embodiment of the invention, when read in reference to theappended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a pictorial view of a data terminal which incorporates thefeatures of the present invention;

FIG. 2 is a partially schematic exploded view of the data terminal shownin FIG. 1;

FIG. 3 is a diagrammatic representation of circuit functions controllingthe operation of the data terminal shown in FIG. 1;

FIG. 4 is a simplified view of a transceiver module and antenna assemblyof the data terminal, depicting particular features of the currentinvention;

FIG. 5 shows a cross section through a radiating element assembly of theantenna shown in FIG. 4;

FIG. 6 is a partial view of the lower end of the data terminal with wallportions of the housing broken away to show a battery compartment ingreater detail;

FIG. 7 is a schematic representation of a battery for the data terminalshowing a preferred contact arrangement;

FIG. 8 is a schematic representation of a radio communications systemincluding data terminals of the present invention and showing one of themodes of operation of the data terminal;

FIG. 9 shows a prior art printer and cradle and the data terminaladapted by features of the present invention to interact with the cradleand printer;

FIG. 10 is a schematic representation of the operation of the dataterminal in a radio communication mode between the printer of FIG. 9 anda central computer; and

FIG. 11 shows schematically another mode of operation of the dataterminal as a coupling link between the central computer and anothercomputer.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, there is shown a pictorial representation of aportable hand-held data terminal which is designated generally by thenumeral 14. In particular, FIG. 1 identifies externally located Workingcomponents, such as a keyboard 15, an alphanumerical display 16 and twoconnectors 17 and 18, respectively.

The described components 15, 16, 17 and 18 are located in an elongateenclosure or housing 19 which is of a size and includes such roundedcontours 20 so as to conveniently fit into an open palm of a personintending to use the data terminal. The housing 19 may be comprised of anumber of shell portions or components to facilitate the assembly of thedata terminal 14. Thus, for a currently preferred embodiment of theinvention, the housing may include front and rear shells 21 and 22,respectively, a top cap 23 and a battery compartment cap also referredto as bottom cap 24. All of the referred-to shell portions of thehousing 19 are preferably of a typical thermo-plastic molding material,such as commercially available material referred to as ABS plastic.

Again in reference to FIG. the front shell 21 of the housing 19 supportsand externally features the keyboard 15. Typically size limitationsimposed by the portability of the data terminal 14 and a need for apractical size for keys 25 do not permit a large number of the keys tobe incorporated into the front shell 21. In the preferred embodiment thekeyboard 15 is optionally provided with either twenty-three or fortykeys. The keys 25 are alpha-numerical, meaning that characters of thealphabet as well as numerical characters of data can be entered via thekeyboard 15 to be encoded in typical electronic data formats.

The display 16 is also adapted to display alphabetical and numericalcharacters in combination to form typical character messages. In thepreferred embodiment of the invention, the display 16 is a liquidcrystal display (LCD) providing sixteen lines of display, each linehaving a twenty character capacity. The number of lines on the display16 or the number of characters which can be displayed on each line is,of course, a matter of preference and choice. Thus, an alternateembodiment of the invention contemplates a display 16 having only fourlines of characters.

The top cap 23 of the preferred embodiment shows two connectors 17 and18. The connector 17 is preferably a multiple pin D-sub type connectorwhich is configured according to a RS-232 C standard of the ElectronicIndustries Association, and as such a serial-type data transmissionconnector which may provide connection to peripheral devices which maybe similarly configured to offer either one-way or two-way datacommunication at a data bit rate which cannot exceed 19,200 bits persecond.

The location of the connector 17 in the top cap 23 corresponds to thelocation of the same connector in the first type data terminal, asdescribed in the Background of the Invention. Also, the housing 19 ofthe data terminal 14 in the preferred embodiment of the invention is insize and shape substantially identical to such terminal of the firsttype. Thus, from an outward appearance of the data terminal 14, byintent, there are preferably no discernible differences in form whencompared to the outward appearance of a data terminal of the first type.The external features and shape of the housing 19 are duplicatedincluding such details as the shape of the rear shell 22 which featuresthe rounded contour 20 fitting the palm of an operator's hand identicalto that of the first type data terminal. The conforming shape of thedata terminal 14 permits the data terminal 14 to become coupled to, orused in conjunction with, any of a number of peripheral devices whichmay be or may become available for such other data terminal of the firsttype.

The top cap 23 is also shown to support a second connector 18. Thesecond connector 18 is intended for bar code reader 28 (See FIG. 8) tobecome coupled to the data terminal 14. The use of the bar code reader28 with prior art terminals having RF interfaces and external typeantennae is well known in inventory control operations, for example,wherein such data terminals read and transmit bar code data to updatecomputer data bases on a real time basis. The bar code reader 28 is usedto read the bar codes of merchandise items to quickly and with littlechance for clerical errors identify the items while the actual count ofinventory on hand may be entered via a keyboard, such as the keyboard15. In the disclosed embodiment of the invention, the connector 18 forthe bar code reader 28 is located in the top cap 23 adjacent the RS-232C connector 17. The bar code reader 28 is physically and electricallycoupled through a flexible, coiled cord 29 and a connector 30 to theconnector 18.

It should be understood, however, that the connector 18 could be locatedin a different position of the housing 14, in that the currently shownlocation is one of convenience. It may be preferred to relocate theconnector 18 for reasons of compatibility which may become apparent whenthe use of the data terminal 14 is considered as a whole. For example,the current location of the connector 18 requires the connector 30 ofthe bar code reader 28 to be disconnected from the connector 18 beforethe data terminal 14 can be inserted into a cradle 32 as shown in FIG.9. During typical, hand held operations of the data terminal 14, thecurrently contemplated position of the connector 18 serves to keep thecord 29 away from the keyboard 15 and the display 16 on the front of thedata terminal 14. For such hand-held operation, a hand strip 33,conveniently attached to the rear shell 22 of the housing 19, may beused to prevent an operator from accidentally dropping the data terminal14. The attachment of the hand strap 33 to the rear shell 22 is bettershown in FIGS. 2 and 6.

FIG. 2 shows a partially schematic exploded view of the data terminal 14to show in greater detail some of the major internal components of thepreferred embodiment of the invention. The front shell 21 of the housing19 contains the keys 25 of the keyboard 15. In accordance with knowntechniques, a main circuit board 34 has an upper surface 35 whichfeatures conductive patterns forming normally open contacts 36. A keydepression of one of the keys 25 results in the key 25 conductivitybridging a gap of the open contact 36, causing a closure of such contact36. The correct spacing between the respective keys 25 and contacts 36becomes established when the circuit board 34 is assembled to the frontshell 21. To achieve a compact packing of various circuit components ofthe data terminal 14, a back surface 38 of the circuit board 34preferably supports components of a control circuit 39 shown in FIG. 3.Again in reference to FIG. 2, the contacts 36 are coupled to the backsurface 38 of the circuit board 34 by conductive through connections,such as indicated at 40.

The display 16 becomes electrically interconnected to the circuit board34 when the display 16 is assembled to the front shell 21. An electricalconnection is made in a conventional manner via a compressible connectorblock 41. In the assembled data terminal 14 the block 41 is locatedbetween respective contacts 42 on a circuit board 43 of the display 16and their corresponding contacts 44 on the back surface 38 of thecircuit board 34. A communications circuit board 48 may be coupledadvantageously in a similar manner to the circuit board 34 through aninterposed connector block 49. Other connections, such as electricalleads from the connectors 17 and 18 are made through a cable 51 to theirrespective circuits. The cable 51 is preferably a flat cable. Aconnector 52 couples individual conductor leads 53 of the cable 51 torespective connector pins 54 on the communications circuit board 48.From the circuit board 48, further connections are made, for example,through the connector block 49 to the main circuit board 34.

A major cavity 56 formed by the rear shell 22 of the housing 19 isadapted to receive a transceiver module 57. The circuit of thetransceiver module 57 is a standard transceiver circuit 58, referencedin FIG. 3, which is commercially available for industrial communicationsapplications, for example. The transceiver circuit 58 within the module57 is mounted on a circuit board, not shown. Control, data and power iscommunicated to the transceiver through a cable 59 coupled to aconnector 60 which connects to respective connector pins 61 on the maincircuit board 34. The transceiver is housed in a metal enclosure 62 toprovide RF shielding.

An antenna for the transceiver circuit 58 is designated generally by thenumeral 64. The antenna includes in a preferred configuration first andsecond radiating elements 65 and 66. A lead-out from the transceivercircuit 58 to the first radiating element 65 is through a coaxial cablesegment 67. The first and second radiating elements 65 and 66 arecommunicatively coupled through a coaxial linking cable 68. The coaxialcable segment 67 and the linking cable 68 are miniature-type coaxialleads which can be flexed sufficiently to permit a convenient routingpath within the housing 19. The radiating antenna elements 65 and 66 arelocated, one on each side, within a power or battery compartment 70 ofthe housing 19. The circuits, such as on the communications board 48 andon the circuit board 34 include those conductive elements whichrepresent ground planes and inherently tend to shield against RF signaltransmission. The plastic material of the housing is readily penetratedby RF signals. Thus, it appears advantageous to locate the radiatingelements 65 and 66 outward from circuitry and other elements that mighthave a grounding, shielding or signal deteriorating effect on RFsignals.

In the preferred embodiment, the radiating element 65 is locatedadjacent a side wall 71 of the battery compartment 70, while theradiating element 66 is located adjacent a side wall 72 of the batterycompartment 70. The coaxial cable segment and link 67 and 68 are routedfrom the battery compartment 70 through respective antenna apertures 73and 74 formed in an upper battery compartment partition 75.

The battery compartment 70 is of a dimension to accept five AA-typebatteries in parallel alignment. This is the battery configuration ofnickel-cadmium rechargable batteries being used in the previouslyreferred-to data terminal of the first type. The preferred embodimentcontemplates instead as a self-contained power source for the dataterminal 14 a battery pack 80 which is comprised of three lithium typerechargable batteries 81. The preferred batteries, of a AA-type size,provide in series combination a total voltage of nominally between 9.0and 9.6 volts. This corresponds to the design supply voltage of the dataterminal 14. Hence, the change in the battery type and configurationprovides for additional space to mount the radiating elements 65 and 66on each side of the battery compartment 70. The battery pack 80 isinsertible between the two radiating elements 65 and 66 within thebattery compartment 70.

FIG. 6 shows the battery compartment 70, partially in section and thebattery compartment bottom cap 24 (shown in FIG. 2) having been removedto show the radiating elements 65 and 66 installed. FIG. 6 shows inparticular a positive battery contact 82 and a corresponding negativebattery contact 83 The two opposite contacts 82 and 83 are preferred tobe in two adjacent positions of three possible positions, such that athird position 84 of the three battery positions has no contact. Thepreferred contact arrangement prevents a possible reversal of thebattery pack 80. A preferred arrangement of the batteries in the pack 80is best explained in reference to FIGS. 6 and 7. FIG. 7 showsschematically a preferred configuration of the battery pack 80 and thecontacts 82 and 83 relative thereto. A first one of the three batteries81 in the pack 80 is oriented with a positive terminal 86 against thepositive contact 82. An oppositely outer battery 81 is also oriented inthe same direction as the first one of the three batteries 81. Acorresponding negative terminal 87 of the first battery 81 has attachedthereto one end of a conductive cross strap 89. The other end of thestrap 89 is attached to a positive terminal 91 of the oppositely outerbattery 81 of the pack 80. An insulating shield 92 preferably caps thepositive terminal 91. A corresponding negative terminal 93 of suchoppositely outer battery 81 is conductively connected by a strap 94 to apositive terminal 95 of the center one of the three batteries 81. Theorientation of the center battery is reversed with respect to theorientation of the other two batteries 81, such that positive andnegative terminals 95 and 96 of the center battery are reversed withrespect the respective terminals of the outer batteries of the pack 80.Thus, the negative terminal 96 of the center battery contacts thenegative contact 83. The lower contacts 87, 95 and 93 are shielded fromexternal contacts by a lower battery shield 97.

Advantageously, the described structure of the battery pack 80 and thelocation of the contacts 82 and 83 prevent accidental reversal of thepolarity of the battery pack 80. Thus, if the battery pack 80 isaccidentally reversed about a centerline 98 through the center battery,the center battery will still contact the negative terminal, while thepositive terminal 91 will be adjacent the positive contact 82. However,the shield 92 prevents the terminal 91 from making electrical contactwith the contact 82. Should, during the insertion of the battery pack 80into the battery compartment 70 (See FIG. 6.), the upper and lowerterminals become reversed by accident, the shield 97 would prevent theterminals of the battery pack 80 from becoming electrically coupled tothe contacts 82 and 83, so that the error becomes immediately apparentwithout damage to the data terminal or an explosive reaction because ofa reversal of the battery pack 80.

The schematic block diagram of FIG. 3 illustrates an interaction offunctional elements of the terminal's control circuit 39. A majorelement of the control circuit 39 is a host microprocessor integratedcircuit 101. A preferred microprocessor is an 8051 type circuit. Theoperations of the microprocessor 101 are supported by a number ofsubcircuits. As is often the case, the control functions for themicroprocessor are preferably permanently stored in a Read-Only Memory(ROM) circuit, such as the EPROM 103 which is shown as being coupled tothe microprocessor via a data bus 104. A control program stored in theEPROM 103 provides the microprocessor 101 with control sequences andpriorities for all contemplated operating functions and subroutines ofthe data terminal. The microprocessor 101 is consequently a key elementnot only for controlling all operational modes but also for controllingthe manipulation of data which may need to be processed during theoperation of the data terminal 14 of FIG. 1 in any of its operationalmodes.

Still in reference to FIG. 3, the microprocessor 101 consequentlyreceives, stores, retrieves and processes data from external sources asa result of the operation of said data terminal 14. Such data may bestored temporarily in a random access memory (RAM) 106. The RAM 106 istypically used to temporarily store both procedural and substantivedata. Procedural data are, for example, address codes, statusinformation on currently active, interactively coupled components orinformation relating to operating sequences. Substantive data, on theother hand, would be of the type entered via the keyboard 15 or the barcode reader 28, for example.

Other subcircuit functions are supported, for example, by an addresslatch circuit 107 and a station identifier circuit 108. The addresslatch 107 locks in the identifier value of a current memory address. Thestation identifier circuit 108 generates a station identification codewhich identifies the particular data terminal to a base station 110 (SeeFIG. 8) when the data terminal 14 is used in a typical multiplexingoperation in conjunction with other potentially active data terminals14.

In one mode of operation of the terminal 14, substantive data may becommunicated via a communications circuit 111, referred to in FIG. 3 asCOMM BUFFER, and the RS 232 C Connector 17, the combination of which isalso referrred to as RS 232 C interface or RS 232 port. Datacommunications through the RS 232 port may be incoming or outgoing datamessages communicated in which is commonly known as full or half duplexmodes. The bar code reader connector 18 is coupled to a bar code readerbuffer circuit 112, which circuit may include code interpretationcircuits or may interact with the microprocessor 101 or anothermicroprocessor to interpret and validate data read by the bar codereader 28 before storing them in the RAM 106 or transferring them to adisplay circuit 113 of the display 16. The display 16 and the displaycircuit 113 are adapted to receive and display information from thekeyboard 15, the bar code reader buffer 112, the communications buffer111 or from the transceiver 58, as directed by the microprocessor 101.Data received by the transceiver 58 are demodulated by a filter-buffercircuit 114 and are typically directed by the microprocessor to thedisplay circuit 113 to be displayed on the display 16.

Another mode of operation of the data terminal 14 is as real timeinteractive communication mode with a central computer 115 (as showngenerally in FIG. 10.), in which the data terminal 14 receives andtransmits data messages through its radio communications link. Suchlink, as shown schematically in FIG. 3, is comprised of the antenna 64,the transceiver 58, the FILTER/BUFFER circuit 114 and the microprocessor101. Received data messages pass through the circuit 114 as they arerouted to the microprocessor 101 via DATA IN bus 117. The microprocessor101 is of a type supporting serial transmit-receive functions. Outgoingdata messages or serial data streams are applied directly routed viaDATA OUT bus 118 from the microprocessor 101 to the transceiver 58. Themodulating-demodulating functions of the transceiver circuit 58 preparethe outgoing data messages for transmission via the antenna 64. A thirddirect signal line between the microprocessor 101 and the transceiver 58is a TRANSMIT connecting line 119 which has the function of transmittinga handshake signal between the microprocessor 101 and the transceiver 58to disable transceiver functions. The transceiver functions might, forexample, be disabled for the operational mode during which data messagesare communicated directly via the communications buffer 111 and theconnector 17.

The antenna 64 is depicted in greater detail in FIG. 4. In the preferredembodiment the lead-out connection from the transceiver module 57 to theantenna 64, namely the coaxial cable segment 67, is of a convenientlength for routing along the inside of the already described housing 19toward the battery compartment 70 (see FIG. 2, for example.). The cablesegment exits at a convenient point from the metal enclosure 62 of thetransceiver module 57, preferably somewhat removed from the control,data and power cable 59. The radiating elements 65 and 66 are thenmounted along the sides and within the battery compartment 70, as shownin FIG. 6. Still in reference to FIG. 4, the cable segment 67 terminatesat a coupling 121 which is a base for the first radiating element 65. Ata connection 122 to the coupling 121, a splice 123 couples a first end124 of the coaxial linking cable 68 to the coaxial cable segment 67. Thelength "L" of the linking cable 68 between the splice 123 and a couplingbase 125 adjacent the second end 126 of the cable 68 is currentlypreferred to be equal to one-fourth of the wave length of the carrierwave of the RF signals transmitted through the radiating elements 65 and66. It is believed beneficial in allowing the two radiating elements 65and 66 to be coupled in parallel without increase in the impedance ofthe antenna, in that one of the radiating elements will be phasingthrough peak radiating power when the second radiating element is at anode. A quarter wave length difference at the contemplated radiofrequency, contributed by the length "L" of the coaxial linking cable 67is believed to bring about the desired result. It is, of course,possible to change the length "L" to a different length, such as to athree-fourths wave length delay for a similar result. In the alternativeit may be deemed desirable to choose the coaxial cables to be of lengthfrom a splitting link, such that the radio transmission wave issimultaneously at a peak or at a node at both of the elements 65 and 66.

In the preferred embodiment, the radiating elements 65 and 66 areidentical coiled wire springs 129, the structure of a representative oneof which is shown in greater detail in FIG. 5. A preferred material forthe springs 129 is copper-plated music wire of 0.05 inch diameter. Theuncoiled length of that portion of the music wire of the spring 129 thatextends free beyond the coupling base 121 is chosen to be equal toone-half of the wave length intended to be transmitted by the spring 129as radiating element 65 or 66. Since it is desired to house theradiating element in the space of a size AA battery, a space constraintexists that the coil of the spring 129 should not exceed 0.4 inch indiameter. The coils for the springs 129 for the radiating elements 65and 66 preferably have a slight taper with an average diameter ofapproximately 0.38 inch. With such a diameter, eleven 23 turns of wireare required to coil a length of 128 inch of wire. Such length is equalto a half wave length at a nominal transmission frequency of 460 MHz,hence of the frequency range at which the transceiver circuit 58 wouldbe operating. The total length of the wire for the spring 129 isapproximately 17 inch, allowing for about three turns of the wire to becoiled onto and fastened to a shoulder 131 of the coupling 121. The wireis preferably soldered to the shoulder 131 to become permanentlyattached thereto. An outer end 132 of the coupling 121 may be threadedas is shown in FIG. 5, and the connection 122 may then be a threadedcoaxial connector, or the end 132 may be a smooth-walled and of adaptedto receive ends of the coaxial cable segment 67 and the linking cable 68in a crimped or soldered connection for a permanent attachment of thecoaxial link and cable segment to the radiating elements 65 and 66. Thecoupling 125 is similar to the coupling 121 except for the absence ofthe splice 123 as shown in FIG. 4.

Preferably, both radiating elements 65 and 66 are encased in acylindrical plastic housing 133 which is molded about or attached by anyother convenient method to the respective couplings 121 and 125. Theplastic material chosen for the housing 133 may be the same as that ofthe front and rear shells 21 and 22, or of any other suitable materialwhich is readily penetrable by RF energy. The outer dimensions of thehousing 133 are preferably equal to those of a conventional size AAbattery housing. The housing 133 is preferably closed at the endopposite the coupling 121 by a base cap 134 of circular configuration.The base cap lends rigidity to the cylindrical shape of the housing 133.However, as an alternative embodiment the base cap may be omitted,particularly when the cylindrical housing is of such rigidity so as notto risk damage to the wound shape of the radiating element. Each of theturns of the spring 129 is spaced from its adjacent turn at a pitchdistance "P" which maximizes the available space in the housing 133 suchthat the pitch distance is substantially equal between all adjacentturns of the spring 129. Contained by the overall dimensions of thehousing 133, the radiating elements 65 and 66 fit into the outermostbattery positions of the battery compartment 70 of the housing 19 asshown in FIG. 6.

FIG. 6, showing the lower portion of the housing 19 of the data terminal14 also shows a plurality of contacts 136. The contacts 136 are moldedinto the rear shell 21 of the housing 19 and protrude to the outersurface of the housing 19. The contacts 136 include data input-outputcontacts which within the housing 19 are preferred to be electricallycoupled to the COMM BUFFER 111. The schematic diagram in FIG. 3indicates such arrangement which enables the contacts 136 to serve as analternate data transfer connection for certain peripheral devices, suchas, for example, the data transfer cradle 32 shown in FIG. 9. As suchthe contacts 136 as well as the connector 17 provide data communicationsinterfaces for the direct transfer of data or control messages by directtransfer through communications cables that may be coupled to theoutside of the data terminal 14 via such interfaces. Again in referenceto FIG. 6, the lower end of the hand strap 33 is shown attached to therear shell 22 of the housing 19 by means of a clamping plate 138 andpreferably two flat head mounting screws 139. The upper end of the handstrap 33 is similarly attached by means of the clamping plate 138 andthe two mounting screws 139, as shown in the exploded view of FIG. 2.

One of the modes of operation of the data terminal 14 is best explainedin reference to FIG. 8. Typically, a number of the data terminals 14 maybe employed in conjunction with one of the transceiver base stations110. The transceiver base stations are typical commercial stationscapable of functioning in a multiplexing mode which allows a number ofthe data terminals to substantially simultaneously exchange datamessages with the transceiver base station 110. The base station 110 maybe wall-mounted or otherwise fixedly attached in a store area orwarehouse. The transceiver base station 110 may be communicativelycoupled from its designated fixed location through a cable 142 to thecentral computer 115. The computer 115 may be located in an office arearemote from the base station 110. When used in typical retailingoperations, the computer 115 may also be hard-wired to various cashregisters. While the cash registers may transmit inventory depletiondata on a real time basis to the computer, the data terminals 14 may beused to enter into the computer 115 existing inventory information orinventory restocking data. In a typically multiplex type operation, eachof the data terminals 14 would receive from the computer 115 via thebase station 110 uniquely addressed data messages, such that typicallyonly one of the data terminals 14 can decode a respectively addressedmessage from the computer 115. Also, data encoded by one of the dataterminals 14 into data messages and transmitted to the base station 110ar uniquely identifyable by the base station 110 and by the computer,after being rout ed from the base station through the cable 142, ashaving been originated by that particular data terminal 14.

In an interactive mode, an operator of one of the terminals may inputinto the data terminal 14 via the bar code reader typical S.K.U. (StockKeeping Unit) numbers. The data read into the terminal 14 will appear onthe display 16 and will also be temporarily stored in the RAM 106. Theoperator may then enter additional data via the keyboard 15, such as forexample a quantity of the respective stock item which may have just beenadded to replenish depleted inventory. Upon a command to transmit thedata, the data terminal assembles the entered data into a data messageand transfers the message to the transceiver circuit 58 fortransmission. The base station 110 routinely samples each data terminal14 and receives the transmitted data message to forward it to thecomputer 115.

Instead of merely entering data into the computer by radio frequencytransmissions, the data terminal 14 is capable of requesting informationfrom the computer and have the information transmitted to appear on thedisplay 16. The data terminal 14 consequently can be programmed toaccess certain or all data on the computer 115 to have available for itsuse the computing power of the computer 115. In stock-keeping operationsdepletion rates and restocking forecasts may be obtained. In retailoperations price checks can be obtained on a real time basis.

In a further operational mode of the preferred embodiment, the dataterminal 14 may be inserted into the cradle 32 of a printer 145. Thecradle 32 uses contacts (not shown) which become coupled to the contacts136 of the data terminal 14. The cradle 32 connects the data terminaldirectly, meaning by typical hard-wired connections, to the printer 145such that the printer can be operated via the keyboard 15. Typicallyprinters such as the referred-to cradle and printer combination havebeen used with data terminals of the first type for printing orderreceipts or invoices in delivery route operations. In such operations,the driver enters the order or delivery confirmation and prints a hardcopy for the customer's records. The printer 145 is typically capable ofbeing operated from DC supply such as available on a delivery truck.

When the data terminal 14 is inserted into the cradle 32 is possible topower the terminal 14 through power supplied to the printer, such asfrom the electrical system with which the printer 145 is powered. Insuch instance it may be possible to recharge the terminal 14 while theterminal is located in the cradle 32.

The data terminal 14, when used in combination with the cradle 32 andthe printer 145, enables the printer to be used as a portable customerservice station in a number of service operation where portability isrequired and customer receipts need to be printed. In such combinationalarrangement, the printer 145 and the data terminal 14 function as asingle unit. Moreover, inasmuch as the transceiver 58 is acommunications link to the central computer 115, an even more versatilecombination is formed. The data terminal 14 inserted into the cradle 32,as shown in FIG. 9, connects the computer 115 to the printer 145 via theradio data link provided by the data terminal 14. The computer 115 hasavailable in its storage peripheral various data files with product,inventory, pricing and customer information. The computer 115 mayfurther be connected through conventional modems and telephone lines toobtain customer credit information. Thus, FIG. 9 shows a portablecustomer service station with the capability of receiving customercredit card data, charging a customer's account and printing a customerreceipt on a completed transaction. FIG. 10 is a schematicrepresentation of the combination of the data terminal 14 inserted intothe cradle 32 of the printer 145 interactively communicating with thecomputer 115 by means of the base station 110.

FIG. 11 shows a use for the data terminal 14 inserted into the describedcradle 32. In the schematic diagram of FIG. 11, the cradle 32 is coupledto a computer 148. The computer 148 ma be a portable computer or may bea computer or data terminal which has accumulated a large volume of dataover a period of time, but has no direct link to the central computer115. By inserting the data terminal into the cradle 32, the computer 148becomes coupled directly to the data terminal 14 and thereby to thecentral computer 115 via the radio link established by the data terminal14 and the base station 110. With the setup as shown in FIG. 11, it ispossible to download accumulated data from the computer 148 directly tothe central computer 115. Also, if the computer 148 is used foroperations which require routinely updated information, it is possibleto update information by temporarily coupling the data terminal 14 tothe cradle 32 of the computer 148 and to download such updatedinformation by radio communication through the data terminal 14 from thecentral computer 115 to the computer 148.

While the foregoing invention has been described in terms of a specific,preferred embodiment thereof it is to be understood that various changesand modifications can be made in any of a number of ways in thedescribed embodiment without departing from the spirit and scope of theinvention. This invention is to be defined and limited only by the scopeof the claims appended hereto.

What is claimed is:
 1. A compact, hand-held data terminal adapted tocommunicate data in any of at least two communication modes, theterminal comprising:an elongate housing including a battery compartmentat a lower end thereof; means for manually entering data and datadisplay means disposed in a front face of said housing andcommunicatively coupled to each other; means including externallydisposed electrical contacts mounted in said housing said electricalcontacts communicatively coupling the data terminal directly toexternally located peripheral devices upon insertion of the dataterminal into a data cradle for transferring data in a first, directdata transfer communication mode between the terminal and externallylocated peripheral devices; a transceiver module disposed within saidhousing; a control circuit including means for storing control sequenceinstructions, means for storing data and means for selectivelycommunicating data between said data storage means, said data displaymeans, said transceiver and said data transfer means; and antenna meanslocated within said housing, said antenna means comprising at least oneantenna element coupled to the transceiver module and disposed along theside of and within the housing and spaced from the control circuit andthe transceiver module, whereby the antenna becomes disposed away fromradiation shielding surfaces of the control circuit and the transceivermodule and remains within the confines of the housing to permit theinsertion of the data terminal into a data cradle of a peripheral devicefor communication therewith in the first mode while being capable ofcommunicating via the transceiver module and the antenna means in asecond RF communication mode with a further external peripheral device.2. A compact, hand-held data terminal according to claim 1, wherein themeans for transferring data includes a serial-type data transmissionconnector, the terminal further including a bar code reader connectorsuch that a bar code reader upon being connected to the bar code readerconnector becomes electrically coupled to the terminal to read bar codedata into the data storing means of the terminal.
 3. A compact,hand-held data terminal according to claim 1, wherein the at least oneantenna element comprises a heroically wound radiating element having anuncoiled length of one half of a wave length of the operating carrierwave of the transceiver module.
 4. A compact, hand-held data terminalaccording to claim 3, wherein the at least one radiating elementcomprises a pair of radiating elements each of which being respectivelylocated along one of two opposite side walls of the battery compartmentof the housing.
 5. A compact, hand-held terminal according to claim 3,wherein the helically wound radiating element is located along a sidewall of the battery compartment of the housing and is encased in acylindrical antenna housing of a material penetrable by RF energytransmission, the antenna housing occupying the space of a batteryelement in the battery compartment.
 6. A compact, hand-held dataterminal of the type having an elongate housing, a keyboard and analphanumeric display disposed in a face of the housing, input-outputdata connector terminations having first externally accessible connectorelements for communicatively coupling the data terminal to datainterfaces of data handling equipment, data processing and controlcircuit means located within the housing for receiving data from theinput-output connector terminations and from the keyboard and forstoring and transferring data to the connector terminations, andself-contained power means located within a power compartment formed aspart of the housing of the data terminal and coupled to the controlcircuit means for providing operating power to the control circuitmeans, wherein the improvement comprises:a transceiver module includingan antenna located within the housing, the antenna having at least oneradiating element, the radiating element being a helically wound elementlocated along at least one edge of the housing of the data terminal, anda coaxial cable connecting an antenna terminal in the transceiver modulewith the at least one radiating element of the antenna, such that thedata terminal may be inserted without hindrance from an antenna into adata cradle of a peripheral communication device, the data cradle uponinsertion of the data terminal therein establishing data communicationbetween the data terminal and a corresponding peripheral communicationdevice, and circuit means including a second connector elementterminating externally of the housing for coupling a bar code reader tothe data terminal when the data terminal is operated externally of thedata cradle, the circuit means adapted to accept data from a bar codereader connected to the bar code reader connector element fortransferring such accepted data to the data processing circuits of thedata terminal.
 7. A compact, hand-held data terminal according to claim6, wherein the helically wound antenna element has an uncoiled length ofone half of a wave length of the operating carrier wave of thetransceiver module.
 8. A compact, hand-held terminal according to claim7, wherein the helical antenna element is disposed along at least oneedge of the power compartment of the housing away from radiationshielding surfaces of the transceiver module and the data processing andcontrol circuit means.
 9. A compact, hand-held data terminal accordingto claim 7, wherein the helical antenna element is encased in acylindrical housing.
 10. A compact, hand-held data terminal according toclaim 6, wherein the at least one radiating element of the antennacomprises two radiating elements, both elements being helically woundradiating elements, the elements being linked by a length of coaxialcable of one-forth of a wave length of the carrier wave at the operatingfrequency of the transceiver module, the length of the coaxial cableextending along the length of the elongate housing, the radiatingelements and the transceiver module being disposed at substantiallyopposite ends of the data terminal.
 11. A compact, hand-held dataterminal according to claim 10, wherein the helically wound antennaelement has an uncoiled length of one half of a wave length of theoperating carrier wave of the transceiver module.
 12. A compact,hand-held data terminal according to claim 11, wherein the helicallywound antenna element is encased in a cylindrical housing.
 13. A compacthand-held terminal of the type having a housing, a keyboard and analphanumeric display disposed in a face of the housing, a transceivermodule located within the housing, data processing and control circuitmeans located within the housing and coupled to the transceiver modulefor receiving data from the transceiver module and from the keyboard andfor storing data, circuit means coupled to the data processing andcontrol circuit and including a connector element terminating externallyof the housing for coupling a bar code reader to the terminal, thecircuit means adapted to accept data from the bar code reader when thebar code reader is connected to the bar code reader connector elementfor transferring such accepted data to the data processing circuits ofthe terminal, and self-contained power means located within the housingand coupled to the control circuit means for providing operating powerto the control circuit means, wherein the improvement comprises:anantenna located within the housing and coupled to the transceivermodule, the antenna having at least one radiating element; andinput-output connector means terminating externally of the housing andbeing coupled to the data processing and control circuit forcommunicatively coupling the terminal to data interfaces of externaldata handling equipment, the housing of the terminal being of a size tofit a data cradle for coupling the terminal via the connector means toexternal communication devices, whereby the antenna being within thehousing facilitates the terminal being inserted into the data cradle.14. A compact hand-held terminal according to claim 13, wherein theradiating element is a helically wound antenna element having anuncoiled length of one half of a wave length of the operating carrierwave of the transceiver module.
 15. A compact, hand-held terminalaccording to claim 14, wherein the helically wound antenna element isencased in a cylindrical housing.
 16. A compact, hand-held terminalaccording to claim 13, wherein the data cradle is electrically coupledto a printer, whereby the terminal, upon its insertion into the cradle,becomes enabled to communicate with the printer, such that data enteredvia the terminal are communicated to the printer for printing and theoperation of the transceiver of the terminal enables data message from acentral computer to be printed by such printer.
 17. A compact, hand-heldterminal according to claim 13, wherein the input-output connector meanscomprise a plurality of contacts molded into and protruding to theoutside of the housing, adapted to interface with the data cradle, thedata cradle being electrically coupled to a first computer, whereby theinsertion of the terminal into the cradle couples the terminal to thefirst computer, thereby enabling the first computer to communicatethrough the data terminal, the transceiver module of the data terminal,and a communications link with a second, central computer.
 18. Acompact, hand-held data terminal according to claim 6, wherein thehousing includes a user's hand-fitting rounded contour for holding theterminal, and wherein the at least one radiating element is disposed atan end of the housing away from the rounded contour for holding theterminal.